Horton

Re: Skipping logical replication transactions on subscriber side

Masahiko Sawada <sawada.mshk@gmail.com>

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From: Masahiko Sawada <sawada.mshk@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>, Greg Nancarrow <gregn4422@gmail.com>, "tanghy.fnst@fujitsu.com" <tanghy.fnst@fujitsu.com>, "osumi.takamichi@fujitsu.com" <osumi.takamichi@fujitsu.com>, Alexey Lesovsky <lesovsky@gmail.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>, vignesh C <vignesh21@gmail.com>
Date: 2021-11-24T08:19:40Z
Lists: pgsql-hackers 
On Wed, Nov 24, 2021 at 12:13 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> On Wed, Nov 24, 2021 at 7:51 AM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> >
> > On Thu, Nov 18, 2021 at 12:52 PM houzj.fnst@fujitsu.com
> > <houzj.fnst@fujitsu.com> wrote:
> > >
> > > On Tuesday, November 16, 2021 2:31 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> > > > Right. I've fixed this issue and attached an updated patch.
> > > >
> > > Hi,
> > >
> > > I have few comments for the testcases.
> > >
> > > 1)
> > >
> > > +my $appname = 'tap_sub';
> > > +$node_subscriber->safe_psql(
> > > +    'postgres',
> > > +    "CREATE SUBSCRIPTION tap_sub CONNECTION '$publisher_connstr application_name=$appname' PUBLICATION tap_pub WITH (streaming = off, two_phase = on);");
> > > +my $appname_streaming = 'tap_sub_streaming';
> > > +$node_subscriber->safe_psql(
> > > +    'postgres',
> > > +    "CREATE SUBSCRIPTION tap_sub_streaming CONNECTION '$publisher_connstr application_name=$appname_streaming' PUBLICATION tap_pub_streaming WITH (streaming = on, two_phase = on);");
> > > +
> > >
> > > I think we can remove the 'application_name=$appname', so that the command
> > > could be shorter.
> >
> > But we wait for the subscription to catch up by using
> > wait_for_catchup() with application_name, no?
> >
>
> Yeah, but you can directly use the subscription name in
> wait_for_catchup because we internally use that as
> fallback_application_name. If application_name is not specified in the
> connection string as suggested by Hou-San then
> fallback_application_name will be considered. Both ways are okay and I
> see we use both ways in the tests but it seems there are more places
> where we use the method Hou-San is suggesting in subscription tests.

Okay, thanks! I referred to tests that set application_name. ISTM it's
better to unite them so as not to confuse them in future tests.

Anyway, I'll remove it in the next version patch that I'll submit soon.

Regards,

-- 
Masahiko Sawada
EDB:  https://www.enterprisedb.com/

Commits

  1. Test ALIGNOF_DOUBLE==4 compatibility under ALIGNOF_DOUBLE==8.

  2. Reorder subskiplsn in pg_subscription to avoid alignment issues.

  3. Add ALTER SUBSCRIPTION ... SKIP.

  4. Optionally disable subscriptions on error.

  5. Update docs of logical replication for commit 8d74fc96db.

  6. Respect permissions within logical replication.

  7. Fix regression test failure caused by commit 8d74fc96db.

  8. Add a view to show the stats of subscription workers.

  9. Add logical change details to logical replication worker errcontext.

  10. Rename LOGICAL_REP_MSG_STREAM_END to LOGICAL_REP_MSG_STREAM_STOP.

  11. Fix typo in protocol.sgml.

  12. Remove unused argument in apply_handle_commit_internal().

  13. Fix replication of in-progress transactions in tablesync worker.

  14. Reorder pg_sequence columns to avoid alignment issue